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-   -   help on convergency.. (http://www.cfd-online.com/Forums/fluent/31542-help-convergency.html)

heydari May 26, 2003 03:55

help on convergency..
 
Dears, I have simulated a jet flow but as I enlarge my domain, the created vortex expands too. The iteration no exceeds 4000 but the convergency, remains to approx. 0.1 with some periodic changes. the vel. and pressure changes in one point do not reach to a constant value. thanks for helping me...

Colin May 26, 2003 14:31

Re: help on convergency..
 
Hi, Heydari. I also posted a question about convergency some days ago, and I get a kind reponse form AP. Here are his suggestions, hope they could give you some help. ================================================== ========== Re: Convergence Question

Posted By: ap <apnews@infinito.it>

Date: Wed, 7 May 2003, 6:51 p.m.

In Response To: Convergence Question (Colin)

Hi Colin, I don't know the problem you're solving, so I'll try to give some general advice.

- First of all you should check if your problem is well-posed. Verify all boundary conditions.

- Check your grid and refine it, if necessary.

- If you're doing unsteady calculations, try to reduce time step and/or increase the number of iteration per time step.

- Try to reduce under-relaxation factors.

- Try different discretization schemes.

- Change solver settings in the Solve->Multigrid dialog box (read the manual for more info).

Hi

ap

heydari May 28, 2003 05:49

Re: help on convergency..
 
Dear Colin, Thanks for your advice, I have checked those recommendations, but the answer is not gotten better.


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